Press



Dec. 3, 1940; M, MAESER 4 2,223,454

' PRESS Filed March 10, 1939 4 Sheets-Sheet 1' M. MAESER" Dec; 3, 1940.

PRESS Filed March 10, 1959 4 Sheets-Sheet 2 WI/E/VTUF W Dec. 3, 194-0.

M. MAESER PRESS Filed March 10, 195.9

4 Sheets-Sheet 3 Fig.5

M57, 1,; WW

M. MAESER Dec. 3, 19 40,

PRESS I Filed March 10} 1939 I 4 Sheets-Sheet 4 Fig.4.

Patented Dec. 3, 1940 mass Mieth Maeser, Beverly, Mass, assignorto United I ShoeMachinery Corporation, Borough. of Flemington, N. J a corporation of New Jersey Application March 10, 1939, Serial N0.-260,959

15 Claims.

This invention relates to improvements in presses, particularly to those presses generally referred to as clicking machines, which are employed for driving dies through thin sheet material such as leather, in forming shoe parts.

As ordinarily constructed, such machines have an upper presser member with a pressing surface smaller in area. than the cutting block on which the material tobe operated upon is held. 'To enable the machine to act upon a die on any part of the cutting block, the presser member or beam is mounted for swinging movement on a vertically reciprocable post positioned rearwardly causing the presser member to deliver the most effective possible blow to the die, thereby improv- 25 ing the quality of the work done, and decreasing the amount of work spoiled because of poor cuts.

Experiments have shown that the most satisfactory drive for a clicking machine is that which;

imparts to the die a sharp, quick blow as contrasted with a slower but heavier pressure on In the types of clicking machine now the die. ingeneral use the driving mean-s is an eccentric and eccentric strap, and each revolution of the eccentric imparts a complete cycle of downward and upward movement to the presser member. The eccentric is arranged so that the side farthest from its axis, 1. e., the high side, is at the top in starting position; On account of the nature of eccentric movement the point of maximum downward velocity and acceleration of the presser member occurs when the.eccentric has rotated through 90 and the presser member is decelerated during the next 90 of rotation. Since the die' is not struck until the'presser is almost at the bottom of its downward stroke, 1. e., at about 120 of rotation, it will be readily seen that the machine does not strike the die at the most desirable moment, namely, when the presser is traveling .at its greatest speed. Consequently all 50 power used to build the speed of the presser memloosely pivotedfor swinging movement about the post, and means 'for reciprocating said post so constructed and arranged that the major part of the downward portion of the reciprocatory movement is continuouslyaccelerated. i 5

By continuing to accelerate the presser mamber beyond 'the first half of its downward stroke, it is made certain that the presser member will strike the die at a -moment when it is either accelerating or is traveling at its maximum velocity rather than when it is decelerating. 'The' necessity of building up excess speed toin'sure suflicient speed at the moment thedie is struck is thusentirelyeliminated l Another obstacle to the satisfactory operation of machines *of this sortlies-in the fact that the. operator, in order to increase his speed of pro.- duction, will frequently actuate the starting mechanism before the horizontal movement of the beamhasstopped. The consequent combination of horizontal and downward movement results in the delivery of a diagonal blow rather than a straight one. In extreme cases, the presser member maystrike only apart of the die; The disadvantages'of this are obvious. The cut is apt to be rough, and generally ofpoor quality, the die may be moved sideways slightly, or one I side of the die may be embedded in the cutting block. In addition, if a double edge die is being used, a diagonal blow tends to turn the upper edge of the die against which the presser member strikes, and thus dulls the die.

Accordingly, another feature of the invention comprises braking means carried by the post and operable by the continuous acceleration of'the downward, movement of, the presser member, said braking means acting to prevent further hori-' zontal movement of the presser memberonce the latter has begun its downward movement.

, By providing ,such braking mechanism, all hori-, zontal movement of the presser member is stopped once the'machine has begun its cycle of opera tion and the possibility of diagonal blows iseliminated. Furthermore since the. continuous acceleration of the presser member causes the, braking means to function, the action .of the latter is positive and does not depend on the operator for its effective use. 1

' The invention will be further described with reference to the accompanying drawings, in which- Fig. 1 is a side elevation of 'a clicking. machine,a portion being broken away to show the. cam drive; Y 1

Fig. 2 is a front elevation of the machine, por- .member rests.

tions being broken away to show the cam drive and the means for adjusting the cutting block;

Fig. 3 is a plan view of the machine; and Fig. 4 is a chart of the driving cam.

As shown in Figs. 1 and 2, the machine comprises a frame ID the forward portion of which supports a cutting block l2, on which the sheet material L to be operated upon is held. The cutting block l2 may be raised or lowered to suit the height of the die l4 and the thickness of the work by means of a hand wheel I5 connected by a pair of worms (not shown) and worm wheels I6 to jack screws [8 on which the cutting block is supported. The mechanism disclosed for adjusting the height of the cutting block is essentially similar to that disclosed in Letters Patent of the United States No. 2,021,138, issued November 19, 1935, on the application of Milton H. Ballard and Donald G. McLean.

Positioned over the cutting block is a. presser member or beam 20 mounted onapin 22 in one end of a post 24; The post is arranged for vertical reciprocating movement and is held in position against horizontal movement by a rear guide surface 26, side guide surfaces 28 and a front guide plate 30 afixed to the frame H] by bolts 32. The lower end of the post is hollow and forms a yoke 34, which serves as a support for an axle 36 carrying an upper cam roll 38 and an axle 40 carrying a lower cam roll 42. A cam 44, with which cam rolls 38 and 42 are engaged, is mounted on a drive shaft 46. Loosely mounted upon the outer end'of the shaft 46 is a fly wheel 48 adapted to be continuously driven by a belt or by an electric motor, not, shown, and arranged to be operatively connected, upon actuation of a starting handle 49, by means of a clutch 50, of

the type disclosed in the'above-mentioned Patent ting block l2. 'The presser member 20 extends rearward from 'the pin 22 for a short distance only, and is so constructed that its center of mass is located well'forward of the pin.

The pin 22, which serves as a mounting for the presser beam, is threaded into a boss 52 on the post 24, and holds the presser member in place on the post by means of a head 54 and a flange 56, the latter being fitted into a cup shaped spherical bearing surface 58 in the presser member. As. shown in an exaggerated state in Figs. 1 and 2 for purposes of illustration, the presser member fits loosely on the pin, so that it can tilt or rock rearwardly about horizontal axes to a slight extent. In order to insure freedom of rotation of the presser member about the pin, roller bearings 60 are provided near. the top of the pin, and at thebottom is located a ball thrust bearing 62 against which a boss 64 on the presser On the rearmost portion of the post is positioned an arcuate braking surface or track 12 which is concentric with the pin 22. Directly above the track on the under surface of the rear of the presser member is a slight projection 14, arranged so as to be over a portion of the braking track 12 at all times, regardless of the position of the presser member 20. When the presser beam 20 is at rest in its normal orlupmost position, there is a small clearance of a few thousandths of an inch between the projection 14 and braking surface 12.

As has already been stated, cam 44 is mounted on drive shaft 46 which is carried on bearings 16 in the rear wall 18 of the frame I0 and in a supporting member integral with the wall. The cam 44 is mounted on the drive shaft 46 in such position that the portion of its periphery nearest to the axis of rotation, i. e., that part in the vicinity of 0 in Fig. 4 is at the bottom when the machine is at rest. During the initial portion of its rotation, the cam imparts no movement through post 24 to presser member 20. At the point indicated by 35, however, there is begun V a rapidly accelerated downward movement which reaches its peak velocity at approximately The downward movement is continued at this velocity during the next 30, during which time the presser member strikes the die. Deceleration occurs between and at which time presser member 20 has been carried to its lowest position. From 140 to 215, there is a dwell during which no movement'i's imparted to the presser member, and at 215 the presser member 20 begins its return to normal position, which return is complete at 320. The remainder of the revolution of the cam 44 is a dwell.

It will be noted that there is a dwell in the cam 44 for a considerable distance either side of its normal position of: rest at 0. In practice it sometimes happens that the clutch will permit the cam to overrun somewhat, or will stop it before it reaches its normal position of rest. The dwell at this point thus insures that'the presser member will stop in its upmost position, without beginning a second downward movement which might endanger the hands of an operator.

. In operation, sheet material'L is placed on the cutting block l2 and a die l4 set on it in the desired position, the presser member or beam 20 being swung to one side at this time. The operator then grasps handle 49'or any other convenient portion of the presser member or beam and swings the latter into position directly over die l4. The operator then depresses handle 49 which is connected to a lever 82 having a forked end 84 making engagement with a link 86. The link 86 is pivoted at 88 on the frame and has a rearwardly extending portion 90 which is connected to the clutch Why a link 92, the handle being held in normal position by a spring 94.

As cam 44 begins to rotate, it draws post 24 downwardly, tightening the fit between the flange 56 and bearing surface 58. Since the machine is operated at a speed such that the downward acceleration of the post 24 and the presser member 20 is greater than the gravitational acceleration, the inertia of the presser member comes into play, offering considerable resistance to the downward pull of the post.

As has been pointedout, the presser member is supported on the pin 22 well rearward of the center of mass of the presser member, so that, in accordance with well-known physical principles, when the beam is pulled down at its point of support adjacent to its rearward end at a rate faster than the rate of gravitational fall, it tends to rock rearwardly. In other words the downward pull of the post operates to overcome the inertia of the rearward portionof the presser member before the forward portion is affected. Since the loose fit of the pin 22 permits slight movements about horizontal axes the presser member rocks rearwardly to apredetermined extent to bring its braking surface 14 into engagement with the braking surface 12 on the post. The frictional engagement thus created between the braking surfaces prevents further horizontal movement of the presser member so'tl-i-at the latter must, of necessity, deliver a perpendicular blow to the die. Furthermore, since the presser member strikes the die when the cam 44 has rotated through approximately the blow will "be delivered when the presser member 2-0 is moving at its maximum velocity as is shown by Fig. 4.

It 'will thus readily be seen that the invention provides a simple, sure means of avoiding glancing or diagonal blows on the die and the disadvantages attendant thereupon. Furthermore the efiiciency of the machine will be at a maximum since the presser member strikes the die when traveling at its peak velocity instead of at a time when the presser member is decelerating as is the case in the type of machine now in general use.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a clicking machine, a vertically reciprocable post, a presser member pivoted on said post by means permitting slight tilting about horizontal axes, means for reciprocating said post, and a braking surface carried by the post and constructed and arranged to engage with a corresponding surface on the bottom of the presser member as the presser member begins its. downward movement.

2. In a clicking machine, a swinging presser beam, means for imparting a continuously accelerated downward movement to said presser beam,

and a brake constructed and arranged to check.

swinging movement of said beam and actuated by said continuously accelerated downward movement of said presser member.

3. In a clicking machine, a presser beam, a cam constructed and arranged to impart to said presser beam a continuously accelerated downward movement, and means actuated by said continuous downward acceleration for preventing horizontal movement of said presser member after it has begun its downward movement.

4. In a clicking machine, a vertically reciprocable post, a presser member mounted to rotate on and to reciprocate with said post and to rock slightly about axes substantially horizontal, cam rollers connected to said post, a cam constructed and arranged to impart to said cam rollers acycle of motion comprising a dwell and a continuously accelerated downward movement, and a braking surface constructed and arranged to engage the bottom of said presser member when the inertia of said presser member causes it to rock horizontally as said presser member begins its downward movement.

5. In a clicking machine, a vertically reciprocable post, a presser member mounted for horizontal swinging movement on said post by means permitting slight tilting of said presser member about horizontal axes and having its center of mass spaced from said post, cam rollers connected to said post, a drive cam constructed and arranged to' impart a continuously accelerated downward movement to said rollers, and an arcuate braking surface carried by said post and constructed and arranged to engage a similar surface on the bottom of said presser member on the side of said post opposite from the center of mass of said presser member when the inertia of said presser member causes it to tilt slightly as it begins its downward movement.

6. In a clicking machine, a vertically reciproca ting post, a I presser member piv otally mounted for swinging movement on; said post by means permitting slight tilting about horizontal axes,

and an arcuate braking track carried by'said post constructed and arranged to engage with'the bottom of said presser member andhaving its center of curvatureat said post. i

- '7.In a clickingmachine, a vertically reciprocating post, a presser member mounted for horizontal swinging movement on said post by means permitting slight tilting of said-presser member about horizontal axes, and an arcuate braking surface carried by said post and spaced apart from a similar surface on said presser member a slight' distance such that when inertia causes said presser member to tilt'as it begins its-downward movement the two surfaces will engage with each other. I i I I 8. In a clicking machine, a vertically reciproeating post, -a cutting block, a presser member mounted" for horizontal swinging movement on said post by means permitting slight tilting of said presser member about horizontal axes and having its center of mass located above said cutting block, and an arcuate braking surface carried by said post and spaced apart from a similar surface on the bottom of said presser member a slight distance such that when inertia causes said presser member to tilt as it begins its downward movement, the two surfaces will engage with each other.

'9. In a clicking machine, a work support, a presser member mounted for movement from a position away from said work support to a position where it effects an operation upon a work piece on the work support, and means for imparting to said presser member a downward movement which is continuously accelerated from the beginning of the movement to the operation on said work piece, and which maintains its maximum velocity for a substantial part of its operation on said work piece.

10. In a clicking machine, a vertically reciprocable post, a presser member loosely mounted for swinging movement on said post, a curved bearing surface carried by said post, a complementary recess in said presser member such that said presser member may tilt slightly about horizontal axes, and means for imparting to said presser member a continuously accelerated downward movement.

11. In a clicking machine, a work support, a vertically reciprocable post, a presser member resting on the upper end surface of said post, a

pin loosely securing said presser. member for swinging movement on said post, a head on said pin having a spherical bearing surface, a complementary recess in said presser member such that said presser member may tilt slightly about horizontal axes, and means for imparting to said presser member a downward movement which is continuously accelerated up to the moment of impact with a work piece on said support.

12. In a clicking machine, a vertically reciprocable post, a presser memberpivotally mounted on said post, a curved bearing surface carried by said post, a complementary recess in said presser member such that said presser member may tilt slightly about horizontal axes, said presser member having its center of mass spaced apart from said post, and means for imparting a continuously accelerated downward movement to said presser member such that the inertia of said presser member will cause the latter to tilt asit begins said downward movement.

7 downward movement.

-14. In a press of the character described for cutting blanks from thin sheet material comprising a work table and a presser member adapted to strike a blow on a cutting die positioned over work on said table, and means for accelerating the presser member during its downward movement, said work table being positioned relative to the vertical movement of the presser member so that the presser member will momentarily engage the die to strike a sharp blow thereon at a time when'thepresser member has attained its maximum velocity and is-almost at the end of its downward stroke. n

15. In a press of the character described for cutting blanks from thin sheet material comprising a work table and a presser member adapted to strike a blow on a cutting die positioned over work on said table, cam rollers 'con-, nected to said presser member, and, a cam in engagement with the rollers for driving the presser member, the portion of said cam in engagement with said rollers during downward movement of the presser member having its radius increased sufiiciently to accelerate and maintain the presser member at a maximum velocity throughoutan angular displacement of the cam greater than 90 so that the presser member will engage the die at a time when the presser member has attained said maximum velocity. MIETH MAESER. 

